Your question is too general: how easy or difficult it is to get a visa depends on:
a. which citizenship(s) you currently hold
b. which country you want to visit
c. the purpose of your visit
d. the length of your visit
e. proof of financial support for the duration of your visit
f. proof of intent to leave the country at the end of your visit

Your answers to these questions will determine what you must do to apply for the appropriate visa and what documentation you must provide in support of your application. A good place to start is to check the website for the embassy or consulate of the country you wish to visit that handles visa applications for where you live now.

Your question is too general: how easy or difficult it is to get a visa depends on:
a. which citizenship(s) you currently hold
b. which country you want to visit
c. the purpose of your visit
d. the length of your visit
e. proof of financial support for the duration of your visit
f. proof of intent to leave the country at the end of your visit

Your answers to these questions will determine what you must do to apply for the appropriate visa and what documentation you must provide in support of your application. A good place to start is to check the website for the embassy or consulate of the country you wish to visit that handles visa applications for where you live now.